<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <script src="/js/vue.js"></script>
    <title>demo3-7</title>
    <style>
        .classA{color:red;}
    </style>
  </head>
  <body>
    <div id="app">
      <div v-bind:class="{'classA': isRed}">我是v-bind命令,绑定class属性</div>
      <div v-bind:style="{fontSize: size + 'px'}">我是v-bind命令,绑定style属性</div>
    </div>
  </body>
  <script>
    var vm = new Vue({
     el:"#app",
      data:{ 
        isRed: true,
        size: 20
      }
    })
  </script>
</html>